Endoscopic devices for surgical or diagnostic procedure are already known. These devices are operated by the surgeon who directly imparts to the device the forward motion through the patient's body. Surgical and/or diagnostic instruments which are necessary to carry out each specific procedure, such as microarms, microcameras, and/or laser emitters are generally associated to these devices.
In order to make easier the surgeon's task there have been proposed endoscopic devices of the above mentioned type capable of a semi-autonomous movement within the body cavity of a patient, adapting their shape, as far as possible, to the shape of the surrounding cavity. In this case, the walls of the body cavity act as a support for propelling the device forward. For example, in U.S. Pat. No. 5,398,670 there is disclosed an endoscopic instrument substantially formed by a bellows-shaped tubular body, capable of extension and retraction, and by two end portions including respective inflatable balloon members, by means of which the front end portion and the rear end portion alternately engage by compression with the walls of the body cavity through which the device must be pushed forward. There is provision for a control system which operates the inflation and deflation of the two balloon members and the extension and retraction of the tubular body according to a sequence such as to produce the advancement of the device in the prefixed direction.
An endoscopic device of the same type is disclosed in U.S. Pat. No. 5,906,591, in which, however, a vacuum pressure sufficient to produce, under the induced sucking conditions, a substantial anchorage of the front and rear end portions to the cavity wall is created sequentially around these end portions.
When the endoscopic device of the type described in the above cited patents is destined to the locomotion through the gastro-intestinal tract, its anchorage to the cavity walls is not satisfactory, because this type of cavity is soft, slippery and often wet. Using balloon-type endoscopic devices such that according to U.S. Pat. No. 5,298,670, even if the intestinal wall is overextended, it is impossible to produce sufficient traction forces due to extremely low friction coefficient of the gastrointestinal tract. Furtheremore, excessive overextension of the balloon will result in causing severe pain for the patient. A similar result is obtained by increasing the suction in the case of the endoscopic device of U.S. Pat. No. 5,906,591, with the drawback that, when the degree of vacuum is increased over a certain extent, undesirable lesions may appear.
In order to improve the anchorage of the endoscopic devices of the above mentioned type it has proposed to equip them with auxiliary anchoring means of various shapes, which, however, increase the structural complexity and the length of the device and increase the patient discomfort and the risk of damage of the involved tissues.